[R]efuses to leave her home not by choice
Can you clarify what this means please? Is she under house arrest? Is she being illegally held captive in her home? Other?
If you can't get her to respond to your care or to accept the care of family and friends, reach out to a third party (professional help: doctor; social worker; etc...). They would be better equipped to handle someone is such dire emotional position. At this point, don't wait to long before finding serious help for this person. To hell with family pride or circumstances.